The present disclosure relates to optical tissue analysis devices. More particularly, the present disclosure relates to optical probes for intraoperative tissue analysis.
In current state-of-the-art neurosurgery, the main challenge in brain tumor removal lies in identifying and removing the brain tumor margins (i.e. the boundary between tumor tissue and healthy tissue) while not the damaging healthy brain tissue. However, identifying tumor margins accurately during surgery is deemed challenging. Tumor removal often relies on the experience of the surgeon in identifying the tumor and its margins. However, in order to avoid damaging and removing any healthy brain tissue, surgeons will only try to remove most of the tumor instead of removing more tissue than the identified tumor.
Recently, Raman spectroscopy has been demonstrated that it can identify brain tumor margins through detecting the unique, “fingerprint” like, chemistry signature from the tumors. However, these high resolution, high power, and highly sensitive Raman spectrometer, or Raman system, are not stable and ergonomic enough to be used in an operation room environment. The design of these Raman systems also requires the tissue to be placed in close proximity (<1 cm) to the optical detection port to achieve a strong detected Raman signal from the tissue. This is difficult for open surgery if the tissue of interest is far away from the top of the opening. In non-open surgery, such as port-based surgeries, this design is not practical to be used in the operation room.
Some Raman systems, with lower resolution, lower power or lower sensitivity, can be used to identify tumor and tumor margin. These Raman systems require a long integration time (>1 min) to obtain a sufficiently strong Raman signal from the tissue to enables differentiation between healthy and tumor signatures. To differentiate between endogenous Raman signatures of healthy tissue and tumor tissue, statistic techniques may be used. Nevertheless, the accuracy of such approaches is constrained by difficulties in detecting a clear difference in the Raman spectra between healthy tissue and tumor tissue.